Oxygen lance assembly



M. PRESTON Sept. 19, 1967 OXYGEN LANCE AS SEMBLY 2 Sheets-Sheet 1 Filed June 22, 1964 INVENTOR. MARTIN PRESTON ATTORNEY Sept. 19, 1967 M. PRESTON OXY GEN LANCE ASSEMBLY 2 Shets-Sheet 2 Filed June 22, 1964 INVENTOR. MART/N PRES TON ATTORNEY removed from the converter.

United States Patent ()fifice 3,342,471 Patented Sept. 19, 1967 3,342,471 OXYGEN LANCE ASSEMBLY Martin Preston, Oakland, Calif., assignor to Kaiser Industries Corporation, a corporation of Nevada Filed June 22, 1964, Ser. No. 376,718 7 Claims. (Cl. 26634) This invention relates to an improved lance assembly for use in metallurgical processes.

In the production of metals, particularly steel, refining may be accomplished by blowing a stream of oxygen downwardly onto the surface of a bath of molten metal contained in an open mouthed converter. Refining is accomplished by reactions which include oxidizing impurities to form gas and floating insoluble oxides. The reactions are violent and they produce dust laden and poisonous gas in large quantities :which must be confined and directed away from the converter for cooling and disposal. A converter is charged and discharged by being tilted from its vertical position, but during the oxygen blowing period of the process it is necessary for the lance to extend into the converter.

Oxygen converting processes have many difficulties associated with them. One is that the gas collecting enclosure or hood that is used must be positioned closely over the mouth of the converter and accordingly the lance used for blowing oxygen must extend through the hood. Simple inexpensive hood structures such as vertical right cylinders cannot be employed because there is no way to introduce the lance, and even with hood structures which are not axially aligned with the vertical axis of the converter, the lance ordinarily must be extremely long in order to reach through an opening in the hood to the position it should occupy during conversion. Long lances are unstable in the sense that they wobble, and they require tall manipulation equipment in order to be Long lances and tall manipulation equipment besides being expensive, create diflicult problems in placing and maintaining the lance at closely controlled positions above the surface of the metal bath.

This invention overcomes or greatly mitigates the aforementioned problems. This invention relates to a lance assembly which permits the use of a vertical hood and it includes a lance contained completely within the hood which is manipulated from outside but which is always vertical, and in some embodiments it is always axial with respect to the vertical axis of the converter when it is in converting position. The lance used in this invention is relatively short and it is positioned, held, and manipulated by two vertically spaced, parallel holding elements which extend from the lance toward and through the side of the gas collecting enclosure or hood. The holding elements are characterized by being pivotally connected to the lance, by passing through a pivotal connection in the wall of the enclosure, by being pivotally connected to an external spacing element, and by having at least one of the parallel holding elements capable of carrying fluid streams into the interior of the lance. For example, in refining steel the fluid streams are the oxygen necessary for conversion and cooling fluid such as water. The spacing element may be the pivotal connection through the hood, although the use of a separate,

external element is preferred,

semblies embodying the present invention and are presented as being illustrative of various embodiments of the invention rather than limiting on its scope.

FIG. 1 is a schematic sectional elevationview of a lance assembly embodying this invention along with associated elements of an oxygen blowing apparatus;

FIG. 2 is a schematic sectional elevation view of another embodiment of this invention.

FIG. 3 is an enlarged view of the pivotal and slidable means in the wall of the gas collecting enclosure for holding the lance spacing elements.

FIG. 1 illustrates schematically various elements of this invention in conjunction with an oxygen blowing process. A converter generally designated 10 of conventional size and shape is constructed of an outer metal wall 11 and a refractory lining 12. Trunnions 13 are provided for tilting the converter to discharge finished product and to receive charge for the next blow. A metal bath 15 is maintained in the converter during operation and exhaust gases escape through the open mouth 16.

The hood, or gas collecting enclosure, generally designated 20, is formed of an inner wall 21 and an outer wall 22 with a space 23 between them for cooling liquid. Space 23 is supplied, for example, with cooling water when hot gas is passing through it. The conventional connections for supplying and removing cooling water are not shown.

A water cooled conduit or lance 2.5 is provided for introducing oxygen through lance tip 26 downwardly and vertically onto the surface of the bath 15. Water cooling is usually provided by surrounding the oxygen carrying conduit with concentric pipes to form two annulus-shaped spaces. The innermost of the annular spaces formed by the concentric pipes usually carries cooling water downwardly toward the tip of the lance and the outermost space carries it upwardly and away from the tip of the lance although these streams may be reversed. The lance 25 is connected through fluid carrying pivots 32 and 33, to parallel holding elements 27 and 28 which pass through pivotal connections 30 and 31 and are in turn connected through fluid-carrying pivots 37 and 38 to a spacing element 35. The spacing element 35 may be internally piped to supply fluid to a holding element, for example oxygen may be supplied through line 36 and into holding element 33 by passing through parts of spacing element 35 and pivotal connection 38. Pivotal connection 33 then passes it to the central conduit of the lance from which it discharges through tip 26. Alternatively, fluid may be supplied directly to the holding elements. For example, flexible tube 34 may supply cooling water directly to holding element 27 from which it passes through pivotal connection 32 and into the interior annular space in the lance. The other side of pivot 32 may carry the return cooling water stream through a separate conduit in holding element 27, and the returning cooling water may discharge through a second flexible connection, spaced side by side with respect to flexible connection 34 and therefore not visible in this view.

In one embodiment, the lance assembly may be installed in a panel 39 composed of an inner wall 40 and outer wall 41 and a cooling fluid space 42. Such a panel, which may be held in substantially gas tight relationship with the rest of the gas enclosure 20, is particularly useful in that it permits removal of one lance assembly and insertion of another in a matter of seconds so that repairs to a lance or other portions of the lance assembly may be made without interrupting the use of the converter 10.

In the use of the invention, the lance 25 may be moved to any position between a maximum high position and a maximum low one, two such positions being illustrated in FIG. 1. The broken lines representation shows the lance 25, the holding elements 27 and 28, and the spacing element 35 in a position diiierent than the solid line a representation. The solid line representation is a typical 1 converting position with the lance tip 26 within converter 16 and a short distance above the bath 15. In the raised position the tip 26 of the lance clears the Open mouth 16 of the converter and the uppermost position of the lance is not as high as the uppermost portion of the panel 39, and in the raised position shown in FIG. 1, the converter may be tipped or the lance assembly including the lance, the holding elements, the spacing element and the panel 39 may be removed entirely from the hood. Means are provided to hold the panel 39 firmly in place however, such means are not shown.

In a particularly desirable embodiment of this invention as illustrated in FIGS. 2 and 3, the lance assemby is maintained both vertical and axial with the converter 19. In the embodiment of FIG. 2 the converter assembly generally designated 10 and hood or gas collecting assembly generally designated are the same as those described with reference to FIG. 1. However, the lance assembly is further improved in order to achieve the desirable end hereinbefore mentioned. The lance assembly is held in the hood 20 by a panel 45 which is constructed of an inner wall 46 and outer wall 47, with a cooling liquid space 48 between them. The lance 50 is held by two parallel holding elements 52 and 53 which are connected to the lance 50 by fluid carrying pivots 57 and 58. The parallel holding elements pass slidably through rotating connections 55 and 56 passing outside of the hood assembly and connecting to spacing element 6%) through fluid-carrying pivots 62 and 63.

As described with reference to FIG. 1, the holding element 57 is supplied with fluid directly through flexible tube 59 While the lower holding element 58 is supplied indirectly through internal piping from flexible tube 61, and through. spacing element 60 and pivot 63.

FIG. 3 illustrates in greater detail one suitable construction of a slidable rotating element, specifically element 55. The panel member 45 is provided with arcuate elements 71 and 72 which are welded or otherwise attached within the panel 45 to receive cylindrical rotating element 55. The rotating element 55 is constructed of a cylindrical wall 73 and a passageway 75 adapted to receive the holding member 52 in substantially gas tight relationship. In cross section the holding member 52 may be circular or it may comprise, for example, two separate conduits of circular cross section or separate conduits fused to form a figure-eight cross section. The particular shape of a holding element is determined by such factors as mechanical loading and the number of and identity of the fluid streams which it might carry, but the slidable connection is made to match the cross section shape of the holding element. As may be seen, the element 52 may turn through a large angle for the purpose of vertically positioning the lance 50 and it is capable of sliding in and out through the rotating element 55 thereby positioning, the lance 50 with respect to the center of the converter 10..

Returning to FIG. 2, a guiding means, shown as rail 65 having an extending portion 66, is provided and interconnected With a roller 67 that rides on portion 66 and is held to the spacing element 60 by a connection 68. As the spacing element 60 is moved up and down, it is guided to move through a horizontal dislocation established by the shape of the guiding element 65. The guiding element 65 may be, for example, back-to-back angle irons and it is bent to a predetermined shape designed to move the holding element 60 through suflicient horizontal dislocation to maintain the lance 50 always on the vertical axis of the converter 10. Thus, in the embodiment of FIG. 2 the lance 50 may be positioned in an infinite number of vertical positions so that the tip 51 i always in proper position with respect to the molten metal 15 depending upon the size of the charge, the characteristics of the charge, and the particular portion of the converting process in progress, and for all vertical adjustments of the lance from maximum extension into the converter to max- 6 imum retraction from the converter it is always axial with the converter 10.

Guide means other than an arcuate rail may be employed, such as a link or series of links connected between a horizontally displacable part of the lance assembly such as a holding element and some stationary portion of the assembly such as panel 45, the length and positioning of such length being adapted to horizontally dislocate spacing element 60 in order to maintain the lance 50 axial with the converter 10.

The guide means as shown in FIG. 2 controls the axial position of the lance 50 through its entire vertical path, however, for most uses it is necessary only to control the axial alignment of the lance 50 in its normal converting positions, for example, in those positions wherein the tip 51 is within the converter. Therefore, the rail 65, need not be as extensive as shown and may desirably disengage roller 67 from the rail when the lance tip 51 clears the vessel to facilitate removal of the lance assembly from the hood 20.

The improved lance assembly of this invention has many advantages over conventional lances currently in use. Among these advantages are:

(1) It eliminates the need for tall and elaborate overhead structures for raising and lowering the lance,

(2) It permits the use of a vertical hood of simple cross section, for example a right vertical cylinder,

(3) It provides positive, two-point support for the lance to assure stable, wobble-free positioning in use,

(4) It assures that the lance is vertical, and

(5) In some embodiments, it assures that the lance is axial, and thereby discharging oxygen against the metal in the center of the converter.

Having thus described this invention, what is claimed is:

1. A lance assembly for introducing fluid into an open mouthed converter having an enclosure in gas-collecting position with respect to the open mouth comprising a vertical lance, two holding elements each pivotally connected at one end to the lance and extending parallel to each other toward and through rotatable means in said enclosure, at least one holding element carrying fluid into said lance, each of said holding elements also being connected pivotally at points lying on a line parallel to said lance and spaced the same distance from each other as the pivotal connections on said lance, and means for introducing said fluid into the fluid carrying holding element.

2. The apparatus of claim 1 wherein said rotatable means are contained in a removable panel in said enclosure.

3. The apparatus of claim 1 wherein said points on a line parallel to said lance are pivotal connections to a separate spacing element external to said enclosure.

4. The apparatus of claim 1 wherein said rotatable means slidably receive said holding elements.

5. The apparatus of claim 1 wherein both of the holding means carry fluid into the lance through fluid-carrying pivots.

6. The apparatus of claim 4 wherein guide means lead the spacing element through an arcuate path designed to maintain said lance axially with said converter.

7. The apparatus of claim 6 wherein said guide means comprises an arcuate rail.

References Cited UNITED STATES PATENTS 1,582,224 4/1926 Prout 74-103 2,093,666 9/1937 Vogt 26635 X 3,030,903 4/1962 Morris.

3,057,616 10/1962 Wohlfahrt et a1. 266-34 X 3,062,523 11/1962 Knuppel 26634 JOHN F. CAMPBELL, Primary Examiner.

R. F. DROPKIN, P. M. COHEN, Assistant Examiners. 

1. A LANCE ASSEMBLY FOR INTRODUCING FLUID INTO AN OPEN MOUTHED CONVERTER HAVING AN ENCLOSURE IN GAS-COLLECTING POSITION WITH RESPECT TO THE OPEN MOUTH COMPRISING A VERTICAL LANCE, TWO HOLDING ELEMENTS EACH PIVOTALLY CONNECTED AT ONE END TO THE LANCE AND EXTENDING PARALLEL TO EACH OTHER TOWARD AND THROUGH ROTATABLE MEANS IN SAID ENCLOSURE, AT LEAST ONE HOLDING ELEMENT CARRYING FLUID INTO SAID LANCE, EACH OF SAID HOLDING ELEMENTS ALSO BEING CONNECTED PIVOTALLY AT POINTS LYING ON A LINE PARALLEL TO SAID LANCE AND SPACED THE SAME DISTANCE FROM EACH OTHER AS THE PIVOTAL CONNECTIONS ON SAID LANCE, AND MEANS FOR INTRODUCING SAID FLUID INTO THE FLUID CARRYING HOLDING ELEMENT. 